Pink Salmon Collapse Blamed on Fish Farming

Mark Hume - National Post
Wednesday, September 25, 2002

VANCOUVER - A near collapse of pink salmon runs in the Broughton Archipelago, where more than three million fish failed to return to spawning rivers this fall, is being blamed on fish farms in the area.

Close to 30 farms, which raise Atlantic salmon in open sea pens, have clustered in the bays and inlets on the approaches to spawning streams in the region, on the mainland coast off northern Vancouver Island.

Alexandra Morton, a biologist who has long been a critic of fish farms, said yesterday the farms have created a perfect winter breeding ground for sea lice, which flourish in the farms because of the concentration of fish and artificial lighting.

She held a press conference yesterday with the Coastal Alliance for Aquaculture Reform, a coalition of 10 organizations opposed to open-ocean fish farms on the B.C. coast.

"In the spring, there are clouds of literally billions of lice larvae coming out of these farm pens," Ms. Morton said.

"Sea lice are natural in the environment. They infect the farmed fish and then they explode in numbers over the winter because the conditions are just right. They moved back to the wild stocks last spring, just when the pinks were migrating through.

"This is not a theory. I've done the science on this."

Salmon farmers deny the allegation, however, saying the research is skewed.

Odd Grydeland, President of the B.C. Salmon Farmers Association, said he has serious doubts about Ms. Morton's research.

He said weak and sick salmon are the ones most likely to be infected by sea lice, and once infected, are the easiest to catch.

"They are ones that are swimming slowly, near the surface, where you can easily dip net them."

Mr. Grydeland said he accepts that Ms. Morton collected many specimens of infected wild salmon last year, but felt her results were badly skewed by catching only sick fish.

He pointed out that last year the rivers in the Broughton Archipelago had big spawning runs of salmon. "Salmon farms have been in that area for 17 years and the wild salmon have been thriving," he said.

Ms. Morton said she collected thousands of young pink salmon last spring along 240 kilometres of coastline, and found all those in the vicinity of fish farms to be infected with apparently lethal levels of parasites.

"I was getting 30, 40 lice per fish -- the highest was 68 on one fish," she said, noting just a few lice can weaken a young fish.

Last year, based on her samples, Ms. Morton predicted an 80% decline in the runs of pink salmon that return to spawn in the late summer after just one year at sea.

"I was wrong," she said in an interview. "It was much worse than I predicted. What we are looking at now is a 99% decline."

Ms. Morton said wild salmon runs can collapse for a number of different reasons, including poor survival rates of the spawners in the rivers, the death of eggs in spawning gravel, and massive die-offs of stocks at sea, in the open Pacific, where water temperatures and feeding supplies are crucial factors.

But she said ocean survival rates were good this year, judging by returns to other rivers and the numbers of young salmon emerging from the rivers last spring appeared to be very strong.

The Kakweikan River had a spawning run of 1.6 million pink salmon in 2000, which should have led to a similar return this year. Instead, only a few thousand fish came back. Similarly, the Glendale River had a run of over 1.2 million -- but again only a few thousand survived to return. The Wakeman and Ahnuhati Rivers, which had a combined total of about one million spawners two years ago, had marginal runs this year.

Overall, said Ms. Morton, 3.6 million pinks should have returned to rivers in the area -- but just 57,000 fish came back.

She explained big runs of pink salmon are environmentally important because the carcasses of the spawned-out fish enrich the rivers and provide food for wildlife, including bears, kingfishers, otters and mink. When the young pink salmon emerge in the spring, and migrate to the ocean, they become a prime food source for other salmon species.

"This is going to cause a domino effect," she said of the pink collapse. "The bears [in the Broughton Archipelago] are starving now. The coho [salmon] will be starving in the spring."

Ms. Morton, who lives in the area, said it is not unusual for salmon runs to vary in size from year to year, but this collapse is massive.

"There has never been an event like this in my area since 1958, when the Department of Fisheries and Oceans began collecting data."

Ms. Morton called on the government to launch an independent investigation into what happened, and urged officials to force salmon farms to move away from salmon spawning streams.

John Radosevic, president of the United Fishermen and Allied Workers Union that represents many fish farm workers, said he is worried by Ms. Morton's findings.

"Our organization does not oppose fish farms ... but we are concerned by what we see as a reckless disregard for wild stocks," he said, referring to a recent provincial government decision to end a moratorium on fish farm expansion on the West Coast.

Mr. Radosevic said his union doesn't want the industry to expand until environmental issues are addressed.

He said trading off wild salmon for farmed salmon doesn't make sense because British Columbia has paid a high price protecting its rivers from industrial pollution and forgoing hydro dams, in order to save wild salmon.

Mr. Grydeland said fish farms do have sea lice infestations, but they are treated rapidly, killing the lice.

And he said that the Atlantic stocks farmers use are raised in freshwater before being transferred to the ocean pens.

"Sea lice don't survive in freshwater. So when we put those fish in the pens, they are clean from parasites. The sea lice they get come from the wild."

Mr. Grydeland said research is underway to determine the migration patterns of wild fish, to see exactly how and where they interact with fish farms. Until all the data are in, he said, it's unfair to blame fish farms for an outbreak of lice in wild stocks.

Bill Otway, a member of the B.C. Wildlife Federation, said it's impossible to conclude salmon farms are to blame, because there have been reports of pink salmon declines in other areas, where there are no farms.

"Pink runs are down markedly from what was expected. I understand that is coastwide, not just in the Broughton Archipelago. The trouble is, DFO isn't producing the data we need to know. There could be a problem. I don't know."

Federal fisheries officials did not return phone calls by deadline yesterday.


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